This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Conventional T1 and T2 imaging techniques are useful for observing late structural morphological changes to the cartilage within the femoral-tibial joint but are insensitive to early biochemical changes. T1[unreadable] MRI has shown promise as a diagnostic measure of early osteoarthritis. The T1[unreadable] relaxation time constant is sensitivity to the interaction between bulk water molecules and extracellular matrix macromolecules such as the proteoglycans in articular cartilage. Meniscal tears are becoming exceedingly common in the modern active teenager, especially younger females. It has been shown that teenagers who have had meniscal tears develop OA at a higher incidence rate than individuals without these injuries in later stages of life. In this study, we evaluate the biochemical changes of stifle cartilage from surgically induced meniscal tears in sheep. It is predicted that these meniscal tears alter the biomechanical loading conditions of the joint and induce stresses believed to cause OA. We will follow the progression of OA within the joint and begin to develop an applicable treatment to mitigate OA development.